Radio button on selection screen

I created a group of radiobuttons (4) on my selection screen. Depending on which radiobutton is selected, certain fields must be available for input and mandatory and others must be greyed out. The problem is that SAP issues a message 'Fill required fields' in between selecting these radio buttons. You cannot change the radio button selection without filling the required fields first. Is there any way to overcome this problem?

I make fields visible/invisible when different radiobuttons are selected. you can loop at the screen and set field attributes similar to code below (Not sure what to do about 'obligatory' unless you edit on the fly):
LOOP AT SCREEN.
IF p_somd = 'X'
OR p_sos = 'X'.
IF screen-name = 'P_WERKS'
OR screen-name = '%_P_WERKS_%_APP_%-TEXT'
OR screen-name = 'P_MATKL'
OR screen-name = '%_P_MATKL_%_APP_%-TEXT'.
screen-active = '0'.
MODIFY SCREEN.
ENDIF. "
ELSEIF p_sodtl = 'X'.
IF screen-name = 'P_LFGJA'
OR screen-name = '%_P_LFGJA_%_APP_%-TEXT'
OR screen-name = 'P_LFMON'
OR screen-name = '%_P_LFMON_%_APP_%-TEXT'.
screen-active = '0'.
MODIFY SCREEN.
ENDIF.
ENDIF.
ENDLOOP.

You could hide all of the fields until the the radio button was
selected. IMO, this would require having a 5th button (to be the
default) indicating that no selection has yet been made. Personally, I
think it would be better to have a second screen with the fields.
Straight dialog programming... - Neal
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